Project Scheduling with Discounted Cash Flows and General Temporal Constraints

Abstract

The net present value is widely regarded as the main financial criterion for evaluating the return on assets and profitability of large scaled projects. Considering activity-on-arc networks, the positive and negative cash flows that occur throughout the project lifetime are associated with the completion of activities. Emphasizing the financial aspects of project management, the activities of the project have to be scheduled such that the net present value of the project is maximized and all temporal and resource constraints are met. For solving the resource unconstrained case, we consider an exact solution procedure based on a first-order steepest ascent approach where the ascent direction is normalized by the supremum norm. Using the concept of minimal delaying modes, we device a branch-and-bound procedure for solving the resource-constrained project scheduling problem with discounted cash flows where we use a dual method to solve the resource relaxation in each node of the enumeration tree. To speed up the procedure preprocessing, immediate selection and a generalized subset dominance rule are used. An experimental performance analysis shows that the proposed algorithms clearly outperforms the procedures proposed in the open literature.